Plan on doing exhaust and headers.
10-09-2006, 08:52 AM
#1
Plan on doing exhaust and headers. I plan on buying longtubes and exhaust before the year ends. I also plan on getting them installed at the same time. Any tips on what I will need as far as the system? Or do most of the systems come with everything? I don't think I will be doing true duals.
10-09-2006, 09:32 AM
#3
TECH Addict
I would say SEARCH - but it appears to be disabled so I'll let you off, lol 
Depends what you go for. You have a 2001 model, so no EGR but you do have AIR. AIR simply pumps fresh air into the exhuast at startup for 20 seconds to a minute, it helps the chemical reaction in the cats to pass emissions tests.
"Race style" headers are exactly the same as "Emissoins headers" except they don't have the EGR (98-00 cars) and AIR fittings on them. There is no performance different.
So you either need to get the emissions headers for your year or get the race spec headers. All depends on whether you plan on running cats or not. No cats and it pointless having AIR.
If you decide to go catless and remove the AIR pump (there's plenty of info on this else where). Then your PCM will throw some codes. These need to be deleted. Many places can do this for a fee, or you can buy some tuning software and do it yourself if you like.
Personally I recommend going for Long Tube (LT) headers. These are best for a n/a setup. Shorties and mid length headers will not see anywhere near the HP gains and are, IMO pointless unless you live in CA, where it's pretty impossible to run LT's.
All LT's will offer about the same performance, main difference is fit & finish and material. Cheap ones are mild steel (you'll want the coated versions) and expensive ones are stainless steel.
Cheap:
-Pacesetter Lt's
-Edlebrock Lt's
Expensive:
-QTP
-Kooks
-Edleborck (brand new out this month)
You'll also need some new manifold gaskets. You want to use the GM style metal gaskets, the paper ones supplied with most headers are junk. You may be able to re-use your existing gaskets, but as the only cost $15 why scrimp and run the risk of having to take the headers off again just to replace a leaky gasket.
o2 exentions, you'll need extensions for your front o2 sensors as they are placed further back, some headers come with these so you'll need to check. The rear 02's aren't usually used with Lt's, this will throw a code so you either need to run o2 SIMS or use tuning software to delete them like the EGR and AIR codes.
Mid pipes, these come in either ORY (off road Y, without CATS) or catted Y pipes. Sadly at present there is no catted Y for the Edlebrock headers, so you;d have to buy an ORY and have CATS welded in place.
Texas Speed & Performance offer a great deal on Pacesetter headers and their own mid pipes. Their catted one uses Magnaflow Carsound CATs. These are pretty decent and will be fine for all cammed LS1's and most h/c setups.
If you plan on BIG power or forced induction (FI) then you really want to look at Metal Matrix CATs (available from Maganflow or Random Technology). They are quite pricey but will be fine and zero restriction even on over 500bhp.
Catbacks. There is a lot of choice and price and personal opinion will dictate what you like and what you don't. www.ls1sounds.com may help you decide. It's generally accepted that the LS1 can sound rather raspy, so running CATs can actually produce a better sound. Failing that an extra bullet muffler or similar may also serve the same purpose.
Popular exhausts:
-GMMG
-Stainless Works chambered
-SLP Loudmouth
-Borla
-Corsa
-Magnaflow
But there are many more.
A good Y pipe setup combined with a good catback will be plenty for most bolt on cammed setups. A mean h/c setup may see more HP with duals or a larger diameter Y pipe setup. Y pipes are proven in competition vehicles just as much as duals are.
N.B.
The Flowmaster American Thunder catback doesn't flow as well as most, it is better than stock and does sound pretty good, but from a performance standpoint it's far from ideal.
Extra's!
Some people have issues with the Y pipe banging on the underside of the car. This is due to the increaed size to 3" diameter and due to engine torquing. Mufflex offer a Y pipe hanger which helps support the Y pipe better. Also its really worth considering replacing the engine and tranny mounts with poly mounts. These are stiffer than the factory rubber ones and are a great upgrade for a performance car regardless, plus having the exhaust and headers off makes fitment a lot easier. But they will also reduce the engine torquing movement. This usually eliminates Y pipe banging. Failing that just a little subtle adjustment of the Y pipe will be needed, maybe with an oxi-acetylene tourch of a BFH (Big F'ing Hammer).
The Mufflex hanger and poly mounts are available from Thunder Racing.
Depends what you go for. You have a 2001 model, so no EGR but you do have AIR. AIR simply pumps fresh air into the exhuast at startup for 20 seconds to a minute, it helps the chemical reaction in the cats to pass emissions tests.
"Race style" headers are exactly the same as "Emissoins headers" except they don't have the EGR (98-00 cars) and AIR fittings on them. There is no performance different.
So you either need to get the emissions headers for your year or get the race spec headers. All depends on whether you plan on running cats or not. No cats and it pointless having AIR.
If you decide to go catless and remove the AIR pump (there's plenty of info on this else where). Then your PCM will throw some codes. These need to be deleted. Many places can do this for a fee, or you can buy some tuning software and do it yourself if you like.
Personally I recommend going for Long Tube (LT) headers. These are best for a n/a setup. Shorties and mid length headers will not see anywhere near the HP gains and are, IMO pointless unless you live in CA, where it's pretty impossible to run LT's.
All LT's will offer about the same performance, main difference is fit & finish and material. Cheap ones are mild steel (you'll want the coated versions) and expensive ones are stainless steel.
Cheap:
-Pacesetter Lt's
-Edlebrock Lt's
Expensive:
-QTP
-Kooks
-Edleborck (brand new out this month)
You'll also need some new manifold gaskets. You want to use the GM style metal gaskets, the paper ones supplied with most headers are junk. You may be able to re-use your existing gaskets, but as the only cost $15 why scrimp and run the risk of having to take the headers off again just to replace a leaky gasket.
o2 exentions, you'll need extensions for your front o2 sensors as they are placed further back, some headers come with these so you'll need to check. The rear 02's aren't usually used with Lt's, this will throw a code so you either need to run o2 SIMS or use tuning software to delete them like the EGR and AIR codes.
Mid pipes, these come in either ORY (off road Y, without CATS) or catted Y pipes. Sadly at present there is no catted Y for the Edlebrock headers, so you;d have to buy an ORY and have CATS welded in place.
Texas Speed & Performance offer a great deal on Pacesetter headers and their own mid pipes. Their catted one uses Magnaflow Carsound CATs. These are pretty decent and will be fine for all cammed LS1's and most h/c setups.
If you plan on BIG power or forced induction (FI) then you really want to look at Metal Matrix CATs (available from Maganflow or Random Technology). They are quite pricey but will be fine and zero restriction even on over 500bhp.
Catbacks. There is a lot of choice and price and personal opinion will dictate what you like and what you don't. www.ls1sounds.com may help you decide. It's generally accepted that the LS1 can sound rather raspy, so running CATs can actually produce a better sound. Failing that an extra bullet muffler or similar may also serve the same purpose.
Popular exhausts:
-GMMG
-Stainless Works chambered
-SLP Loudmouth
-Borla
-Corsa
-Magnaflow
But there are many more.
A good Y pipe setup combined with a good catback will be plenty for most bolt on cammed setups. A mean h/c setup may see more HP with duals or a larger diameter Y pipe setup. Y pipes are proven in competition vehicles just as much as duals are.
N.B.
The Flowmaster American Thunder catback doesn't flow as well as most, it is better than stock and does sound pretty good, but from a performance standpoint it's far from ideal.
Extra's!
Some people have issues with the Y pipe banging on the underside of the car. This is due to the increaed size to 3" diameter and due to engine torquing. Mufflex offer a Y pipe hanger which helps support the Y pipe better. Also its really worth considering replacing the engine and tranny mounts with poly mounts. These are stiffer than the factory rubber ones and are a great upgrade for a performance car regardless, plus having the exhaust and headers off makes fitment a lot easier. But they will also reduce the engine torquing movement. This usually eliminates Y pipe banging. Failing that just a little subtle adjustment of the Y pipe will be needed, maybe with an oxi-acetylene tourch of a BFH (Big F'ing Hammer).
The Mufflex hanger and poly mounts are available from Thunder Racing.